The present invention relates to polyurethane-based reactive adhesives and to their use as one-package adhesive systems.
Heat-curing one-component reactive adhesives based on solid, finely divided polyisocyanates stabilized by coating with polyadducts and isocyanate-reactive compounds, such as polyols and polyamines, are known in the patent literature (cf. for example European patents 62,780, 100,508 and 153,759 and German Auslegeschriften 3,112,054, 3,228,723 and 3,403,499). Hitherto, one of the problems involved in the formulation of heat-curing one-component polyurethane adhesives using such technology has been that adhesives such as these are required to combine high hardness with high heat resistance and a minimal isocyanate demand.
The problem addressed by the present invention was to provide improved polyurethane-based adhesive systems which are suitable for one-component adhesives.